1. Field of the Invention
The present invention relates to fluorescent lamps having shapes that appear to depart from conventional circular cross-sectional configurations.
2. Description of the Prior Art
Fluorescent lamps have previously been devices which are internally partitioned and the arc is confined to a pathway that is essentially circular in cross section. Recent descriptions of such lamps are the compact fluorescent lamps described by Young et al. in U.S. Pat. Nos. 4,185,221, 4,184,101, 4,173,730, 4,182,975 and 3,903,447, and Rogoff in U.S. Pat. No. 4,191,907, wherein metal partitions are employed. Glass partitioning is described in the U.S. patents of LoGuidice, U.S. Pat. No. 3,953,761, Jones, U.S. Pat. No. 3,646,383, Taxil et al., U.S. Pat. No. 3,848,150. Some of these lamps are single ended, compact and fitted with a screw base to mate with the ubiquitous Edison incandescent socket. Partitioning to accomplish the same aims has been attempted by other workers in the fluorescent lamp art dating back to Barclay, U.S. Pat. No. 2,121,133, in 1938. All of the these lamp designs seek to maximize light output by keeping the stationary arc no further than one inch (1") from the phosphored glass surface by means of the partitions. A fluorescent lamp with greater than one inch (1") spacing within the lamp volumes was disclosed by Campbell, U.S. Pat. No. 3,928,786, who switched the arc between multiple electrodes at high frequency. Yamane, U.S. Pat. No. 4,177,401, filled a double cylinder fluorescent lamp by placing a permanent magnet at the exit port of the inner cylinder. Gross and Skeist, U.S. Pat. No. 4,187,446, with magnetic arc spreading techniques, caused the arc to traverse the entire volume of a double cylinder with one or more partitions in a compact fluorescent lamp with a screw base.